Wiper system

ABSTRACT

The invention is directed to a wiper installation, especially for windows of motor vehicles, with at least one wiper rubber which is held in contact with the substrate to be wiped by a clip, wherein the clip is connected with a drivable wiper arm, and a holding area between the wiper rubber and clip is formed as a hinge, wherein a hinge axis extends in the longitudinal direction of the wiper rubber. It is provided that at least one damping element (42) for damping a rotating movement of the wiper rubber (14) is associated with the hinge (40).

BACKGROUND OF THE INVENTION

The invention is directed to a wiper installation, especially forwindows of motor vehicles.

Wiper installations of the type mentioned above are known. As a rule,they have at least one wiper rubber which maintains contact with awindow to be wiped and is movable back and forth between two reversalpositions. For this purpose, the wiper rubber is fastened to a bracketor clip which is connected with a drivable wiper arm. The clip has atleast one claw, generally a plurality of claws which are arranged at adistance from one another along the longitudinal extension of the wiperrubber whose head is held by the claws. The head of the wiper rubber hascorresponding recesses in which the clip can engage.

It is known from DE 975 208 to dimension the head of the wiper rubber sothat, considered in cross section, it is smaller than a space enclosedby the clip. In this way, an articulation or hinge is formed between theclip and the wiper rubber, wherein a hinge axis runs along thelongitudinal extension of the wiper rubber. This arrangement makes itpossible to deflect the wiper rubber during its movement across thewindow due to a frictional force acting at the wiper rubber, resultingin a tilted position between the wiper rubber, in particular a lipcontacting the surface of the window, and the window. This results in amore uniform wiping pattern. In particular, noise generated by the wiperrubber guided across the window is prevented in this way. Correspondingto the back-and-forth movement between the two reversal points of thewiper rubber, a corresponding deflection of the wiper rubber is carriedout in the other respective direction opposite to the wiping direction.The degree of deflection of the wiper rubber is determined by the playof the wiper blade head inside the space enclosed by the clip. Adisadvantage in the known arrangement consists in that noise develops asa result of the head knocking against the clip when the wiper rubberflips over, which happens impulsively due to a sudden change in thewiping direction in exactly the opposite direction.

SUMMARY OF THE INVENTION

The wiper installation according to the invention offers the advantageover the prior art that a development of noise of the type mentionedabove is prevented. Owing to the fact that at least one damping elementfor damping the rotating movement of the wiper rubber is associated witha hinge formed between the wiper rubber and the clip, it isadvantageously possible to dampen the impulsive flipping over of thewiper rubber at least in the area of the head enclosed by the clip, sothat the tilting movement is braked in this area against the force ofthe damping element. In particular, when the entire wiper rubber isformed of elastic material, the lip area contacting the window to bewiped can be flipped over impulsively without this rotational movementbeing transmitted directly to the head of the wiper rubber. Due to thearrangement of the damping element, a tilting movement of the head iscarried out after a delay and with a decelerated impulsive force, sothat the head is prevented from knocking against the clip enclosing itand the noise generated in this way is accordingly prevented.

In a preferred construction of the invention, it is provided that thedamping element is constructed in one piece with the wiper rubber,especially with the head of the wiper rubber. In this way, it is easilypossible to construct the wiper rubbers with an integral damping elementby means of known methods, for example, extrusion of elastic materials.This also reduces expenditure on the construction of damping elements toa negligible amount.

In a further preferred construction of the invention, it is providedthat at least one damping element maintains constant contact with theclip enclosing the head of the wiper rubber. In this way, it is ensuredthat a damping of the tilting movement of the wiper rubber, especiallyin the area of its head, is initiated immediately as soon as the wiperrubber flips over in the reversal positions.

Further advantageous constructions of the invention follow from the restof the features indicated in the subclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic perspective view of a part of a wiperinstallation for motor vehicles;

FIGS. 2 and 3 show a construction, according to the invention, of awiper blade in a first embodiment example; and

FIGS. 4 and 5 show a construction, according to the invention, of awiper blade in a second embodiment example.

DESCRIPTION OF THE PREFERRED EMBODIMENT EXAMPLES

FIG. 1 shows a sectional perspective view of a window wiper installation10 for a window 12 of a motor vehicle. Only an area of the window wiperinstallation 10 showing the fastening of a wiper rubber 14 to a clip 16is shown. The clip 16 is fastened in turn to a wiper arm which can bedriven by driving means, so that the wiper rubber 14 executes aback-and-forth movement between two reversal points on the window 12 ina known manner.

The wiper rubber 14 has a head 18 and a lip 20 which are connected withone another by a bending web 22. The wiper rubber 14 is made of anelastic material, for example, rubber. At least one spring strip 24 isarranged in the longitudinal extension of the wiper rubber 14 and servesto stabilize the wiper rubber 14. As is shown in FIG. 1, the springstrip 24 can be formed as an outer spring strip or, as the followingFigures show, as an internal spring strip 24. The clip 16 has claws 26which are formed from a substantially rectangular or trapezoidal sectionhaving a slit-shaped opening 28 (not visible in FIG. 1) on its sideremote of the clip 16. Gripping portions 30 engaging in groove-likerecesses 32 of the wiper rubber 14 are formed in this way.

During proper use of the window wiper installation 10, the wiper rubber14 is guided across the window 12 by means of the clip 16. There resultsan instantaneous movement direction 34 of the wiper rubber 14. Themovement direction 34 has opposed direction vectors corresponding to thewiping movement of the wiper rubber 14. Due to its construction, thewiper rubber 14 folds over opposite to its movement direction 34.Accordingly, there occurs a blade angle α between a contact face 36 andthe window 12. Angle α is 45°, for example. In this way, the wiperrubber 14 is drawn over the window 12, so that a flawless wiping patternresults on the one hand and a noiseless movement of the wiper rubber 14is made possible on the other hand.

The view in FIG. 1 serves only to illustrate the function of the wiperrubber 14. The construction of the wiper rubber 14 according to theinvention is explained more fully with reference to the following FIGS.2 to 5. FIGS. 2 to 5 show schematic sectional views of the window wiperinstallation 10 in the area of a claw 26 of the clip 16. In thisconnection, identical parts are provided with the same reference numbersand are not explained further.

As is shown in section in FIGS. 2 and 3, the head 18 of the wiper rubber14--considered in cross section--is dimensioned so as to be smaller thana space 36 surrounded by the claw 26. In this way, a free space isformed between the claw 26 and the head 18. Corresponding to the size ofthe free space, the head 18 is supported so as to be rotatable about itslongitudinal axis 38, so that a hinge 40 is formed between the head 18and the claw 26. A maximum angle of rotation β of the hinge 40 isdetermined by the size of the free space between the head 18 and theclaw 26 and by an elasticity of the material of the wiper rubber 14,especially of its head 18.

The head 18 forms damping elements 42. These damping elements 42 areformed by tabs 46 enclosing a hollow space 44 of the head 18. In theembodiment example shown in FIGS. 2 and 3, two tabs 46 are provided,formed in one piece with the head 18, and enclose the hollow space 44.The damping means 42 are formed in the corner areas of the head 18, thatis, in an area which must travel the greatest distance as a result ofthe rotation about the longitudinal axis 38. The tabs 46 arepretensioned in such a way that contact is maintained with the claw 26in every position of the head 38. FIG. 2 and FIG. 3 show the twopossible maximum positions of the wiper rubber 14 and, therefore, of itshead 18. Depending on the movement direction 34, the wiper rubber 14 isflipped or turned over in one direction or the other opposite to themovement direction 34 as was described with reference to FIG. 1. In thereversal positions of the wiper rubber 14, the lip 20 is flipped oversuddenly, i.e., impulsively, by the change in the movement direction 34.Owing to the connection with the head 18 by the bending web 22, thismovement is transmitted to the head 18, so that the head 18 is rotatedabout the longitudinal axis 38. Due to the fact that the tabs 46 restagainst the claw 26, these tabs 46 exert a springing force on the head18 which is opposed to the rotating movement of the head 18 by angle β.In this way, this rotating movement of the head 18 is damped, so that asudden rotation of the head 18 is prevented. Owing to the fact that thetabs 46 rest against the claw 26 at all times, the wiper rubber 14 isguided in the clip 16, particularly in its claws 26, so as to be freefrom play. Depending on the direction in which the wiper rubber 14 flipsover, the damping is carried out by the damping element 42 shown on theleft-hand side or by the damping element 42 on the right-hand side.

FIGS. 4 and 5 show another embodiment example, wherein identical partsare provided with the same reference numbers and are not furtherdescribed. In this case, the damping elements 42 are also formed by fourtabs 46, wherein these tabs 46 are arranged as individual tabs in thecorner areas, viewing the head 18 in cross section. The hollow spacebetween the head 18 and the tabs 46 is formed as a recess 48 with openedges. The tabs 46 are pretensioned in such a way that they contact theclaw 26 at all times, so that the wiper rubber 14 is guided withoutplay. Depending on the flipping over of the wiper rubber 14, tabs 46arranged diagonally opposite one another are compressed, so that therotating movement of the head 18 must be carried out against a springingforce proceeding from the tabs 46, in this case, the diagonally oppositetabs 46. This causes a damping of the rotating movement at angle β.

With reference to the embodiment examples shown in the drawings, it willbe readily appreciated that a guiding of the claws 26 without play isensured on the one hand and a damping of a sudden rotating movement ofthe head 18 of the wiper rubber 14 caused by flipping over is carriedout on the other hand by means of simple measures, namely, the tabs 46which are preferably formed jointly with the wiper rubber 14. The degreeof damping can be adjusted as a function of the shape and/or size of thetabs 46.

Of course, the invention is not limited to the embodiment examples shownherein. The arrangement of other damping means is also possible. Forexample, the damping means can be arranged at the claws 26 which, inthis case, cooperate with the head 18.

What is claimed is:
 1. A wiper installation for windows of motor vehicles, said installation comprising: at least one elongated wiper rubber (14) having a head (18) with a top and a bottom, said head having a plurality of corner areas, a lip (20) extends from said bottom of said head, said lip is adapted to be held in contact with a substrate to be wiped, a clip connected with a drivable wiper-arm, the clip defining a holding area therein for encircling and supporting the head in a hinged manner, wherein a hinge axis extends through the head in a longitudinal direction of the wiper rubber, characterized in that at least two damping elements (42) for damping a rotating movement of the wiper rubber (14) about said axis extend from said head, wherein each damping element (42) is formed by two tabs (46) enclosing a hollow space (44) in opposing corner areas of the head (18), said damping elements lie on opposite sides of a plane which contain said hinge axis and are pretensioned against said claw such that they contacts the claw at all times.
 2. Wiper installation according to claim 1, characterized in that the damping elements (42) are connected with the head in a springing manner.
 3. Wiper installation according to claim 1, characterized in that the damping elements (42) extend from the top of the head.
 4. A wiper installation for windows of motor vehicles, said installation comprising: at least one elongated wiper rubber (14) having a head (18) with a top and a bottom, said head having two corner areas on said top and two corner areas on said bottom, a lip (20) extends from said bottom of said head, said lip is adapted to be held in contact with a substrate to be wiped, a clip connected with a drivable wiper-arm, the clip defining a holding area therein for encircling and supporting the head in a hinged manner, wherein a hinge axis extends through the head in a longitudinal direction of the wiper rubber, characterized in that four damping elements (42) for damping a rotating movement of the wiper rubber (14) about said axis extend from said head, each damping element is formed by a bent tab extending from one of said corner areas of said head and defining with respect to the head a recess, each damping element being pretensioned against said claw such that it contacts the claw at all times.
 5. Wiper installation according to claims 4, characterized in that the recesses are open edged recesses.
 6. Wiper installation according to claim 1, characterized in that the damping elements are formed in one piece with the head (18) of the wiper rubber (14). 